Can Participants Choose Not to Know Potentially Important Information Discovered During Research?

What if the Participant Would Rather Not Know?

Researchers often focus on the possibility that participants will want important information discovered during a study. But receiving information is not always experienced as a benefit.

A participant might prefer not to learn that they have an elevated risk of an untreatable neurological disease. Someone undergoing genomic research may want medically actionable findings but decline information about future conditions they cannot prevent. Another participant may simply decide that they do not want research to become an unexpected source of health information.

Respecting autonomy seems to support that choice. The difficult question arises when the information researchers discover is potentially serious, preventable, or even lifesaving. Does the participant's choice not to know still control?

A Choice Not to Know Should Generally Be Respected, but Exceptional Conflicts Can Arise

Autonomy Includes More Than a Right to Receive Information

Why might someone reasonably prefer not to know?

Researchers should resist assuming that more information is always beneficial. Health-related information can alter how people understand themselves and their futures. It can affect family relationships, reproductive decisions, insurance or financial planning depending on the jurisdiction, and psychological well-being.

The consequences can be especially difficult when no treatment or prevention exists. One participant may value advance knowledge because it permits planning. Another may regard years of living with an uncertain future risk as a burden with little compensating benefit.

Neither response can simply be inferred from the medical importance of the information.

The right not to know grows from the same autonomy that supports disclosure

If researchers respect participants by allowing them to decide whether they want certain research findings, that respect cannot operate only when participants choose disclosure.

Canada's TCPS 2 provides a particularly clear formulation for material incidental findings. Although concern for participant welfare creates an obligation to share material findings, communication can occur only when the participant or authorized third party has consented to receive them, either initially or through ongoing consent. This explicitly places participant autonomy alongside concern for welfare.

CIOMS similarly emphasizes that the informed-consent process should explain whether information derived from research will be returned and recognizes tiered approaches that allow people to choose among categories of information.

Choosing not to know is not the same as refusing medical care

A participant who declines incidental research findings is deciding whether to receive information generated through the research relationship. That is different from receiving an established clinical diagnosis and then declining recommended treatment.

The distinction matters because research procedures may generate information participants would never otherwise have encountered. Broad genomic sequencing, for example, can expose people to information about risks unrelated to the reason they joined the study.

Researchers should therefore avoid framing nondisclosure preferences as irrational refusal of healthcare. The participant may simply be defining the boundaries of what they want research to tell them.

Participants need to make the choice before researchers know the answer whenever possible

The cleanest approach is prospective consent. If a study can reasonably foresee incidental findings, researchers should explain what categories may arise and ask participants whether they want qualifying findings before those findings are discovered.

This prevents the participant's choice from being contaminated by hints about a specific result. Asking someone, “We discovered something potentially serious; do you still want not to know?” has already communicated consequential information.

The broader process for choosing whether to receive incidental findings should therefore be designed prospectively whenever feasible.

A refusal does not require researchers to erase the finding from existence

A participant's decision not to receive a finding concerns disclosure. It does not necessarily determine every aspect of research data handling, documentation, safety oversight, or regulatory reporting.

Researchers may still need to document what occurred, obtain appropriate expert review, report an event internally, or meet another obligation under the protocol or applicable law. The precise requirements depend on the study and jurisdiction.

This distinction is important because “do not tell me” should not be interpreted as “the research team must behave as though the information was never generated.”

The hardest case is a serious and preventable unforeseen finding

Imagine that a participant explicitly declined incidental findings. Researchers later discover an unforeseen, highly reliable finding indicating a serious condition for which prompt intervention could substantially reduce the risk of death or major disability.

Autonomy supports honoring the participant's refusal. Concern for welfare points in the opposite direction.

TCPS 2 directly recognizes this conflict. When researchers have undertaken not to disclose material incidental findings but subsequently discover an unforeseeable material finding that can be addressed through a potentially significantly beneficial intervention, it directs researchers to consult the research ethics board to determine whether sufficient ethical grounds exist for disclosure and, if so, how disclosure should occur.

Actionability makes the conflict sharper

A preference not to receive information about an untreatable condition may be relatively straightforward to respect. The ethical tension increases when disclosure could enable prevention, surveillance, treatment, or another intervention capable of averting serious harm.

This is one reason clinical actionability receives so much attention in return-of-results frameworks. It changes the potential consequences of remaining uninformed.

Still, actionability does not automatically cancel autonomy. It strengthens the welfare-based argument for disclosure and may make ethics consultation especially important when it conflicts with an explicit preference.

Participants may make different choices for different categories of findings

A right not to know need not be all or nothing. Participants might accept serious actionable findings while declining serious non-actionable findings. Others may want reproductive information but decline information about adult-onset disease.

CIOMS discusses tiered consent as a means of giving individuals greater control over categories of information. Where operationally feasible, such an approach can avoid forcing participants into the artificial choice between “tell me everything” and “tell me nothing.”

Preferences can change

A participant who does not want findings at enrollment may change their mind years later. Conversely, someone initially eager to receive all available information may later prefer narrower disclosure.

TCPS guidance treats consent as an ongoing process and recognizes that changing circumstances can affect decisions about receiving material incidental findings. Longitudinal studies should therefore consider whether participants can update their preferences and how the current preference will be identified when a finding arises.

This is particularly relevant in genomic research, where interpretation can change as scientific knowledge develops. NHGRI notes that genomic results may acquire different interpretations over time, creating additional infrastructure and policy challenges for return.

Children and participants lacking decision-making capacity are different

The right not to know becomes more complicated when someone else is legally authorized to decide for the participant. An authorized third party does not necessarily have unlimited discretion to withhold information that is important to the participant's current welfare.

TCPS 2, for example, states that authorized third parties must receive findings for a child that are actionable immediately or during childhood because decisions must be made in the child's best interests. Adult-onset findings can raise different considerations.

Researchers should follow the applicable ethics and legal framework for pediatric research and participants lacking decision-making capacity rather than applying an adult participant's opt-out model mechanically.

The right not to know is different from confidentiality

A participant may prefer not to receive a finding, yet researchers may separately face an obligation to report particular information to an authority or another party. Those are different ethical questions.

For example, certain findings or disclosures may trigger legal reporting obligations depending on jurisdiction. TCPS 2 explicitly notes that incidental findings can sometimes trigger such duties and requires participants to be informed of relevant limits to confidentiality.

Whether confidentiality gives way to a duty to act or report therefore cannot be answered solely by asking whether the participant personally wants the information.

Do not promise an absolute right the study cannot guarantee

Consent language should describe genuine choices accurately. If particular safety procedures, legal reporting duties, or exceptional circumstances can limit nondisclosure, researchers should not tell participants that their preference can never be overridden under any circumstances.

Conversely, vague statements that researchers may disclose anything “important” whenever they choose can hollow out the right not to know. The circumstances and procedures for exceptions should be as clear as the research context reasonably allows.

A Participant Declines Findings, Then Something Important Appears

The difficult part is precisely that both ethical considerations matter. Respecting autonomy does not make welfare irrelevant, and concern for welfare does not make a prior refusal meaningless.

Common Mistakes About the Right Not to Know

Plan for Refusal Before You Discover Something Difficult

If your study may generate incidental findings, do not design only the pathway for participants who say yes. Decide what will happen when someone says no and a consequential finding later appears.

The important practical distinction is between respecting a choice and abandoning responsibility. A researcher can honor a participant's preference while still managing the finding appropriately within the study's ethical and institutional obligations.

When a Participant Does Not Want to Know

Questions About Choosing Not to Know

Respecting Autonomy Includes Respecting a Thoughtful Refusal

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